1. Field of the Invention
The present invention relates generally to a light transmission system for use on a vehicle and more specifically to a light manifold for use in combination with a reflector to form a vehicle taillight.
2. Description of the Related Art
Conventional light transmission systems used for vehicle headlights or taillights typically use a bulb and reflector system. In a bulb and reflector system, a filament of the bulb is placed at or near a focal point of a parabolic reflector. The light emitted by the bulb filament is collected by the reflector and reflected outward to form a light beam. A lens is used to shape the light beam into a specified pattern to satisfy vehicle lighting standards regulations. Typically, in an automotive application a conventional bulb and reflector system collects and reflects only thirty percent of the light emitted from the bulb filament.
Bulb and reflector systems have several disadvantages, including aerodynamic and aesthetic styling; e.g., the depth of the reflector along its focal axis and the height of the reflector in directions perpendicular to the focal axis have greatly limited attempts at streamlining vehicle contour. Additionally, the thermal energy given off by the bulb during operation must be considered and the size of the reflector as well as the material used in its construction vary depending upon the amount of thermal energy generated by the bulb filament. Decreasing the size of the reflector requires use of materials with high thermal resistivity for the reflector.
One approach to developing a headlight for use with the newer streamlined body designs is proposed in U.S. Pat. No. 4,432,039 which discloses an elliptical reflector used to concentrate and focus light on a light bar having a plurality of reflective facets. While this approach may be useful, a certain portion of the light from the reflector escapes reflection at the facets, thus lowering the efficiency of the system. Additionally, such a headlight system requires the use of lens optics to focus the light reflected by the facets.
Thus, there is a need in the art for an efficient light manifold which accommodates both thermal considerations and the space limitations dictated by the vehicular aerodynamic and styling requirements.